Pietenpol-List: calibrating airspeed
Posted: Fri Jan 02, 2004 5:13 pm
Original Posted By: "Richard Navratil"
Happy 2004, Pietenpolers;The list doesn't seem to be working very well, but I'll try this one anyway. It's a post that was on the KRNet a few weeks ago but it's an interesting thing to try if your airspeed indicator doesn't read accurately. Usually there isn't much you can do to realign it with reality, but this is worth a try:========================Hi folksI came across a neat article by Tony Bingelis on the net last night. Do a googlesearch on pitot static error. Tony described a really simple method foradjusting any airspeed error provided you have an external static tube (asdistinct to a fuselage or interior source). He suggested an o-ring be slidedalong the tube. Locating it in front of the little static holes in the tuberesults in a drop in static pressure and an increase in indicated airspeed.Behind the holes leads to the opposite. Distance from the hole determines amountof change. Once the correct position is ascertained, the o-ring is replaced by amore permanent fixture, eg. a small band of metal or filler. I guess somethingsimilar could be obtained on a fuselage side static vent using a small mound ofsomething either in front or behind the hole that can be sanded down accordinglyto suit.I reckon my airspeed [on his KR] is under-reading by about 12 knots in the cruise becausethe static is affected by high pressure under the wing. The above is so simpleand apparently accurate that I can't wait to try it out and compare with a threeleg GPS readout at different speeds. Certainly heaps easier than relocatingtubes etc. It will also hopefully resolve a minor altitude error picked up by myannual transponder check whereby, for example, altitude readout on the ground byslight evacuation of the static to give 1000 feet was not obtained until 1100feet or so in the air.The Martindale Family29 Jane CircuitTOORMINA NSW 2452AUSTRALIA================================Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.netMake your home warm and cozy this winter with tips from MSN House & Home. http://special.msn.com/home/warmhome.ar ... __________
Happy 2004, Pietenpolers;The list doesn't seem to be working very well, but I'll try this one anyway. It's a post that was on the KRNet a few weeks ago but it's an interesting thing to try if your airspeed indicator doesn't read accurately. Usually there isn't much you can do to realign it with reality, but this is worth a try:========================Hi folksI came across a neat article by Tony Bingelis on the net last night. Do a googlesearch on pitot static error. Tony described a really simple method foradjusting any airspeed error provided you have an external static tube (asdistinct to a fuselage or interior source). He suggested an o-ring be slidedalong the tube. Locating it in front of the little static holes in the tuberesults in a drop in static pressure and an increase in indicated airspeed.Behind the holes leads to the opposite. Distance from the hole determines amountof change. Once the correct position is ascertained, the o-ring is replaced by amore permanent fixture, eg. a small band of metal or filler. I guess somethingsimilar could be obtained on a fuselage side static vent using a small mound ofsomething either in front or behind the hole that can be sanded down accordinglyto suit.I reckon my airspeed [on his KR] is under-reading by about 12 knots in the cruise becausethe static is affected by high pressure under the wing. The above is so simpleand apparently accurate that I can't wait to try it out and compare with a threeleg GPS readout at different speeds. Certainly heaps easier than relocatingtubes etc. It will also hopefully resolve a minor altitude error picked up by myannual transponder check whereby, for example, altitude readout on the ground byslight evacuation of the static to give 1000 feet was not obtained until 1100feet or so in the air.The Martindale Family29 Jane CircuitTOORMINA NSW 2452AUSTRALIA================================Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.netMake your home warm and cozy this winter with tips from MSN House & Home. http://special.msn.com/home/warmhome.ar ... __________